The present disclosure relates to electric machines and electrical busses therefor, and methods for their manufacture.
Electric machines may include a stator, a rotor that rotates relative to the stator, and a housing configured to receive the stator and the rotor. The housing typically positions the stator relative to the rotor to channel magnetic flux between the rotor and the stator, and may include a cover configured to enclose portions of the electric machine. Some electric machines also include a fan that rotates in unison with the rotor, and forms part of a cooling system that removes heat from the stator, which typically includes a stator core and stator windings. Generally, each stator winding corresponds to a phase of an alternating current signal. For example, an electric machine having three independent stator windings may be a three-phase electric machine with the phase of each of the alternating current signals being separated from the other two phases by 120 degrees. Similarly, a six-phase electric machine may have six independent stator windings.
Electric machines may receive and/or generate external torque for their operation. Electric machines that receive external torque generally operate as generators, whereas those that generate external torque generally operate as motors. Still other electric machines selectively operate as either a generator or a motor. Electrical current received by an electric machine operating as a motor induces mechanical torque on the rotor; an electric machine operating as a generator generates an electrical current or voltage as a function of a mechanical torque applied to the rotor. In either case, an alternating current may be directed through the electrical windings of the stator in a manner well-understood by those having ordinary skill in the art.
Converting kinetic energy to electrical energy with a generator, or electrical energy to kinetic energy with a motor, can generate substantial heat due to resistive losses and switching losses. Improvements in the design of electric machines to increase energy efficiency, such as by reducing such losses, are desirable.